There is likely to be a clampdown on the illegal use of organophosphate (OP) dip in mobile sheep shower units, a leading animal health consultant has warned.

Speaking to reporters on Monday, Lesley Stubbings said that newly published guidance on sheep dipping gives authorities more ground to enforce rules on the proper use of dip.

Products that have OP as the active ingredient, such as Gold Fleece, are only licensed for use in plunge dippers.

“If people are using showers or jetters, they could feel some enforcement creeping up behind them.

“With this new code of practice officially out there, there will be more action taken against these people,” said Stubbings.

Keeping OP effective

She explained that mobile showers are not fully effective against sheep scab, so using OP dip in these units could lead to mites becoming resistant to the product.

“If we are going to protect OP and keep it working for us, it is absolutely essential that we use it properly,” said Stubbings.

The sheep health expert added that to be an effective treatment, OP dip must reach all sheep scab mites, which live on the skin of infected animals.

“Neither showers nor jetters can do that. There is evidence that they are not effective at getting down to the skin and killing sheep scab mites.”

Stubbings explained that while mobile shower units can partially suppress scab outbreaks, if some mites survive the treatment, it gives them the opportunity to develop a resistance to the OP dip.

“We have to use OP properly,” she maintained. “We know there are already cases of resistance to OP in other parts of the world.”


Bryan Lovegrove from the Animal Health Distributors Association, said the only other treatment for sheep scab is injectable wormers, but that there are already some resistance issues with these products.

“The continued use of showers and jetters will bring about resistance to OP dip. Anybody who is knowingly using showers or jetters should be reported, because it is against regulations,” he said.